Good morning. Happy Tuesday. I have no coffee in hand and it is perfect. All right. Coming up on a very busy Tuesday, we're going to take straight into today's Q&A. This is with Taya. Taya asked a very strong foundational question that pertained to what is basically the lower extremity representations during early, middle, and late propulsion. Seems like a very basic question. The importance of this question though, it comes down to when we intervene. So if we have somebody that has a specific representation and we're trying to make a favorable change in relative motions, it behooves us to number one, understand where they are in the propulsive phase. And number two, what is the representation of the intervention? So for instance, if I had somebody that was presenting with a late propulsive strategy, say on the right side in the right lower extremity, and I perform an activity that reinforces the late representation. That's all fine and good. If that's my intention, if my intention is to alter the relative motions, then I need to understand how I need to reorganize this lower extremity to create an early representation so I can make that favorable change. So again, very, very powerful question. Thank you, Taya, for asking this question. Everybody have an outstanding Tuesday and I will see you guys tomorrow. Hi, Taya.

Happy Tuesday.

Good morning. Coming up on a very busy Tuesday, we're going to take straight into today's Q&A. This is with Taya. Taya asked a very strong foundational question that pertained to what is basically the lower extremity representations during early, middle, and late propulsion. Seems like a very basic question. The importance of this question though, it comes down to when we intervene. So if we have somebody that has a specific representation and we're trying to make a favorable change in relative motions, it behooves us to number one, understand where they are in the propulsive phase. And number two, what is the representation of the intervention? So for instance, if I had somebody that was presenting with a late propulsive strategy, say on the right side in the right lower extremity, and I perform an activity that reinforces the late representation. That's all fine and good. If that's my intention, if my intention is to alter the relative motions, then I need to understand how I need to reorganize this lower extremity to create an early representation so I can make that favorable change. So again, very, very powerful question. Thank you, Taya, for asking this question. Everybody have an outstanding Tuesday and I will see you guys tomorrow. Hi, Taya.

Hi, sir. Yesterday, I was thinking a little bit about this and I realized maybe I don't have everything sorted out in my head. You and me both. Yeah. I think me more than you, but yeah. It's a pretty basic question, I think. I just wanted to go over how the femur and tibia orient during early, middle, and late propulsion. How does the calcaneus orient and the midfoot?

We'll see. You might be way ahead.

It's a pretty basic question, I think. I just wanted to go over how the femur and tibia orient during early, middle, and late? How does the calcaneus orient and the midfoot?

Is that all?

Yeah.

OK. Let's pick a spot first.

Let's go early.

OK. So we're in early. OK. What area are we looking at?

Proximal femur.

Proximal femur. OK. So I'm stepping forward. All right. Which side of the pelvis is ahead? So if I'm stepping forward with my right foot, let's just make it very quick. Okay. I'm stepping forward with my right foot. Okay. Which side of my pelvis is farther ahead?

Right.

Okay. That's kind of obvious, right? Yeah. What direction is my sacrum facing? Left. So if my leg is going straight forward relative to the sacrum, would that hip have to be in an ER or an IR representation?

Yeah.

Perfect. There you go. Problem solved. Okay. So you got that. What are we going next?

Is this the femur?

It's the same. Okay. Yes, but relative to the proximal femur. If my foot hits the ground, what happens?

It orients into internal rotation more than the proximal part. I love that.

I love that. OK. So gravity works. Right. So I land and there's this force that's coming up into the leg, right? I'm in this ER representation approximately, but I'm starting to put force into the ground, which means I have to have a turn inward, right? The connective tissues are starting to absorb energy. And so that's like compressing a spring, isn't it? And so if you look at the, the twisty stuff in the femur, I got this perfect little spring mechanism going on Donna. OK, so that distal femur is going to start to absorb the internal rotation before the proximal femur does, doesn't it? You see it? OK, cool. OK, where are we going next?

Approximal tibia.

OK, so if I'm stepping forward and I just land on the foot and I don't have a lot of weight on it yet, would I be in more of an ERD representation or an IRD representation at the foot? So where would the talus be? Would it be pushing down and in into the ground? Or would it still be sort of up and away from the ground in an ERD representation in that early start? Okay, awesome. Which way would the tibia turn distally relative to that talus? Would it go with the talus?

Yeah.

Awesome. So if the distal tibia was slightly ER'd with the proximal tibia, move into ER. Yeah. Awesome. So now you know where you are relative, right? So you can see it coming up again. So I'm landing in the more ER representation. I'm about to go into a lot more IR, but okay.

So everything is turning to ER. So the IR goes from the ground up.

Yes. The IR is coming from the ground up, gradually. So the earlier you are, the more ER representation you have and the less IR that's superimposed, but the IR is starting to come up. So here's the kicker. Think about the springy thing that we just talked about. What do you want? My dog is yelling at me. Hang on a second. Let me recapture my thought process. So the IR is going to start to come up. But it's coming up from the ground first. I capture my medial contacts on my foot, still in the ER representation, but the IR is now allowed to come up. The distal tibia is going to be biased into an ER, but it's going to start to IR. And it's going to do that before the proximal tibia. Can you picture that?

Yeah. Because of the foot?

Yeah. So there's going to be a differential between the distal tibia and the proximal tibia. So it's going to be more ER represented in the proximal tibia. You can understand that. Okay. And that is a yield. That's actually a yield in the tibia. So part of that is the yielding action that we talk about early where we're starting to absorb that force. That's also going to contribute to the relationship between the distal femur and the proximal tibia is that the tibia is going to be biased towards ER relative to the distal tibia. And it's probably going to be an ER slightly relative to the distal femur. Okay. And then as you move towards middle, now the IR is going to start to be much more represented in all cases. Okay. Does that make sense?

Yeah.